A new collaboration between US rappers Eminem and Dr Dre has leaked online.

'Number One' sees Eminem rap from Dr Dre's perspective on two verses, before switching back to his own personality.

The track, produced by Dr Dre, is purported to feature on Eminem's forthcoming studio album 'Relapse' - although there are also claims it could be intended for the producer's own album.

As previously reported, Dr Dre stopped work on his next studio album, 'Detox', to produce the rapper's new record - the follow up to 2004's 'Encore'.

Speaking last month, Eminem said he was currently in the process of choosing the final tracklist for the album from over 100 recorded songs.

The rapper said he hoped 'Relapse' would “remind people how I rap” but added he had no plans to tour.

The album is due to be released in January.

(by Jason Gregory)